Pressing

The main principle of pressing records from vinyl matter has remained unchanged for several decades. There have, however, been some slight improvements in the technology though, such as electronically controlled presses or automatic production. In a hydraulic press fitted with 2 pre-heated moulds and fitted with stampers, the pre-heated vinyl matter is inserted into the machine sandwiched between two completely dry labels. Once the pressing process is started, the labels and vinyl matter are pressed under a pressure of 100 or more tons at a temperature of 160°C (345°F) for a precise amount of time. The surfaces of the grooved stampers are copied exactly into the vinyl matter. After the pressing mould is sufficiently cooled, the press opens and the vinyl record is removed, trimmed to the required size and visually inspected.

GZ Vinyl has been using proven and reliable manual double-presses from the German company Taunus Ton Technik (TTT) for years. Experienced and skilled operators carry out their work on these machines including a standard visual inspection of each pressed record. In addition to pressing classic black records, manual presses allow us to produce more unique and interesting records with different colours and effects as well as records with full surface picture labels embedded into them (picture discs). In 2012, GZ increased the pressing capacity of black and single coloured records after purchasing several automatic presses manufactured by the Swedish company Alpha Toolex.

Thanks to our own development, since 2014 GZ has been producing vinyl records using new manual presses manufactured in the Czech Republic. First Czech made automatic presses were put into operation in 2016.

Test pressing

Test pressings are highly recommended. They allow for the producer, band, label, etc to check the overall quality of the cut, sound and metalwork used for the production of your records before we press the full amount. Generally, we will send you 5 test pressings - black vinyl records with blank white labels, which you will need to listen to and approve. Once these have been approved, we can continue with the rest of the production.

If, however, you are not happy with the test pressings, then we need to find out what is actually wrong with the sound or identify any other possible problems. If the problems have occurred due to error on GZ Media’s side, we will produce new metalwork (stampers) or re-cut the test pressings using a new master (if required). If the fault is on the customer’s side (due to a badly prepared master source, for example, badly cut lacquer foils or incorrectly manufactured metalwork parts supplied by the customer), then the customer will be liable to pay for new process, should they require new test pressings.

Vinyl compound

Nowadays, the production of vinyl records requires a high quality material which ensures a low background noise so that audiophiles can enjoy listening to their favourite music without the disturbing background noise which was commonly present on records in the past. Most manufacturers of vinyl records must purchase the vinyl compound that they require for pressing their records from 3rd party suppliers, but here in GZ, we produce our own vinyl compound according to our own special formula of raw material. Our specially formulated compound has won several international awards and our GZ brand vinyl is highly praised on both sides of the Atlantic. With the current high demand for vinyl records, GZ has absolutely no problem manufacturing enough vinyl compound to sufficiently cover our production quantity needs.

Surprisingly enough, the production of vinyl records is one of the most accurate and precise amongst all methods of mass production. The finest details carried in the grooves which contain the sound information are more than a thousand times smaller than the width of the groove itself, which can be compared to the thickness of a human hair. Even though we cannot see these details, even under a microscope, the sound is reproduced very accurately by high-quality playback needles. In addition to the quality of the actual pressing material, it is extremely important that the records are handled with care and kept clean when being handled and listened to.

The basic material used in the production of vinyl matter is a powdered copolymer of vinyl chloride and vinyl acetate which is mixed in a fluid mixer with the necessary additives. Stabilizers are added to prevent degradation at higher temperatures as well as lubricants - so that the matter adheres to the pressing tools, a moderator melt flow which adjusts the speed of the flow between the stamper material during pressing and finally, the colour. Classic black records are made from a special black carbon while coloured records are produced using basic colours. We are also mixing several varieties of basic dyes or pigments to create special colours or shades of colours. The resulting powder for creating the pressing matter is piped through special systems which lead to the presses through extruders. When the material comes out of the extruder, its temperature is approx. 165-170 degrees. The matter is kneaded, homogenised and dispensed directly to the pressing machine. It is also possible to use granulated vinyl matter in the extruders.

Quality control

The progress of all processes in GZ is monitored and recorded from the initial entering of an order into the internal system through to the production of the vinyl records and printed parts and finally to the transportation of the goods to the customer. Of course, the supplied audio data and its suitability for the production of vinyl records as well as the preparation and possible correction of supplied graphic materials for printed products - labels, packaging etc are also thoroughly checked. A visual inspection is carried out among all products in the production department and a random sample of each record is chosen for listening after being pressed.

One sample of each pressed record is manually listened to on a regular Sony turntable by a trained quality control employee. This process is carried out in order to identify any possible defects in the stampers or defects which may have been caused during the actual pressing of the vinyl. If the record does not pass this step of the quality control process, the production is scrapped and a new pressing is made until the sample is approved.

In addition to listening to the records in our quality control department, GZ also evaluates the quality of the records using a unique Teldec-Revox control system which can idenitfy certain types of pressing defects as well as a special device which measures the eccentricity of the records.